In 1532, twelve-year-old Esteban, an orphan from Barcelona, possesses a unique ability to command the Sun to shine, earning him the title "Child of the Sun." After his adoptive father passes away, Esteban discovers that he was saved from a sinking ship as an infant. The medallion he has always worn points to a location in the New World, possibly linked to the legendary Cities of Gold. Determined to uncover his origins and find his parents, Esteban sets sail from Spain. On his journey, he encounters Zia, an Inca girl taken from her people years earlier, who wears an identical medallion. They are later joined by Tao, a young castaway from the Galapagos and the final heir to the Empire of Heva, which is said to have created the Cities of Gold. Guided by Coyolite, the radiant star depicted on their medallions, the three children explore the uncharted New World in search of the Cities of Gold, convinced that this path will lead them to their missing parents.